Merge pull request #13 from gondo/patch-1

fixed php warnings

Author: rashid2538

HtmlDiff.php

@@ -266,7 +266,7 @@ private function InsertTag( $tag, $cssClass, &$words ) {
 					$this->content .= $specialCaseTagInjection . implode( "", $this->ExtractConsecutiveWords( $words, 'tag' ) );
 				} else {
 					$workTag = $this->ExtractConsecutiveWords( $words, 'tag' );
-			                if( $this->IsOpeningTag( $workTag[ 0 ] ) && !$this->IsClosingTag( $workTag[ 0 ] ) ) {
+			                if( isset($workTag[0]) && $this->IsOpeningTag( $workTag[ 0 ] ) && !$this->IsClosingTag( $workTag[ 0 ] ) ) {
 			                    if( strpos( $workTag[ 0 ], 'class=' ) ) {
 			                        $workTag[ 0 ] = str_replace( 'class="', 'class="diffmod ', $workTag[ 0 ] );
 			                        $workTag[ 0 ] = str_replace( "class='", 'class="diffmod ', $workTag[ 0 ] );